During the winter, your grass undergoes a great deal of stress. Cold temperatures, freezing ice, and compaction from heavy snow and snowmen building are just the beginning.

Some landscapes have something else to worry about: crown hydration.

Homeowners with poor lawn drainage systems are often the victims of this winter damage— killing their grass and causing a bleak lawn come spring.

We’re here to share all we know about crown hydration, from preventing to recovering from this winter turf damage.

What is Crown Hydration?

Think of crown hydration as a fancy term for “grass freeze.”

During winter, us Massachusetts residents often experience varying fluctuations in temperatures. It’s not abnormal to see a few unusually warm March, April, heck even February days, only to get hit by a cold front a week later!

These brief higher temperatures thaw your frozen soil and confuse your grass, thinking spring is here— and it’s time to wake up. Your grass begins to prepare, sucking up whatever water and nutrients it can to start growing. (This is why the condition has the word “hydration” in its name; the grass hydrates like an athlete getting ready for a race).

Your grass stores this fresh moisture in its crown, the part of its structure that’s level with the soil. When the cold blows in again suddenly, your soil— and as a result, your grass— refreezes.

At this point, your engorged grass is in trouble. The frozen water inside the crown expands and damages the blades’ cell membranes, killing your turf.

Why Lawns with Poor Drainage Are Most Affected

A lawn that isn’t collecting excess water is less likely to suffer from crown hydration.

Your grass blades need to be hydrated to cause this condition. That means the landscape needs to be storing water in its soil when warm temperatures hit.

Properties with poor water run-off systems often collect moisture. This is especially a problem for those with depressed areas in your turf, which pool water.

Preventing Crown Hydration

There are a few important things you can do to prevent dead grass from crown hydration:

  1. Fill in depressed areas late fall. If you have divots in your property from heavy mowing equipment, fill them with soil late fall so they don’t collect water over the winter. Larger sunken or sloped areas can be filled too but may benefit more from improved drainage systems.
  2. Fertilize late fall. Give your lawn the nutrients it needs to survive the winter seasoning strong. An already weakened turf won’t have the resources it needs to survive the harsh cold, but fertilization can help it prepare.
  3. Add potassium to your soil late fall. During the hardening period of late fall, grass with a high potassium diet (a 1:2 nitrogen to potassium ratio) experienced 30% less damage than those without, according to a study by the University of New Hampshire. Not sure how to do this? Our team knows how— just ask.
  4. Improve your lawn drainage. You can welcome better drainage by adding a berm to redirect water flow, place a rain barrel under your downspout to collect rainwater, or— for extreme instances— install an underground French drain. Ask our landscaping team how we can improve your lawn drainage.
  5. Choose plants with good run-off. The grass isn’t the only plant that can refreeze and damage its cell membrane. When planting this fall, choose broad-leaved varieties, which have a canopy over their roots and channel water away.
  6. Shovel or clear snow early. Homeowners who let snow mounds sit on their yards are just asking for water overflow when the melt hits. Avoid piling snow from your walkways onto your grass, or in a place where melt run-off won’t travel to your grass. This is easier said than done!
  7. Be most mindful during the transitional period of winter and spring. Massachusetts homeowners can typically expect winter temperatures to fluctuate most in March, as spring begins. During this time especially, be sure to keep snow off your lawn or water from flowing onto your turf. Remember, your grass can’t suck up excess water that’s not in the soil!

Recovering from Crown Hydration Kill

If you followed our preventative steps and still suffered from crown hydration (or found this article because your grass is already dead!), you, unfortunately, will have to regrow your damaged turf.

Widespread grass freeze may require you to plant all new grass, by aerating and overseeding your entire lawn.

Are You Sure it Was Grass Freeze?

Dead grass post-winter can be the result of a number of conditions, not just crown hydration. For example, yellow grass, come early spring, can be caused by salt damage from potent deicers. And that’s not all.

Name your lawn’s specific problem by reading our Landscaper’s Guide to Regrowing Dead Grass After Winter Damage. It discusses cold desiccation, snow mold, lawn moles and more to help you assess and recover from your wintertime turf woes.

Leave it to the Professionals

Preparing your lawn for winter or refreshing it for spring can be a daunting feat.

Next year, prevent grass damage by marking off your to-do’s on this Massachusetts Winter Landscape Checklist.